Posted by Nicholas Forth
on January 14, 2022
A standard UK single mattress measures 90cm wide by 190cm long, commonly described as 3ft x 6ft3. These measurements refer to the mattress itself, rather than the total size of the bed frame, which will usually be slightly wider and longer depending on its design.
Before buying, it is important to check both the mattress dimensions and the external measurements of the bed, particularly in smaller bedrooms where floor space, doors, wardrobes and bedside furniture can affect the layout. This guide explains the key measurements to check, including the difference between single and small single sizes, UK and European dimensions, and mattress depth. For a broader overview of choosing and styling this size, see our guide to single bed sizes.
What Size Is a Single Mattress in CM?
In the UK, a standard single mattress measures 90cm wide by 190cm long. You will also see this size described as 3ft x 6ft3.
| Measurement | Width | Length |
|---|---|---|
| Centimetres | 90cm | 190cm |
| Imperial | 3ft | 6ft3 |
These dimensions refer to the mattress or sleeping area itself. They should not be confused with the overall dimensions of the bed frame, as features such as side rails, posts, upholstery, headboards and footboards can all increase the amount of floor space the bed occupies.
For this reason, if you are planning a room or replacing an existing mattress, it is best to work from the measurements in centimetres rather than relying only on the term Single.
Is a Single Bed Frame the Same Size as the Mattress?
No. A 90 x 190cm single measurement normally refers to the mattress or sleeping area, not the total external size of the bed frame.
Mattress Size vs Overall Bed Dimensions
The finished frame will usually be wider and longer because the side rails, headboard, footboard and other structural details sit around the mattress. The exact difference varies by design, so two beds made for the same 90 x 190cm mattress can occupy noticeably different amounts of floor space.
This is particularly important in compact bedrooms, where a few extra centimetres can affect access to wardrobes, drawers, doors or bedside furniture.
Why Bed Style Changes the Footprint
A slim metal frame can create a lighter, more open look and may stay relatively close to the mattress footprint. Wooden frames introduce more visible structure and texture, while upholstered beds can feel more substantial because of their padded side rails and headboards.
Endurance Beds Insight: A 3ft bed refers to the mattress width, not necessarily the finished width of the furniture. Always use the external dimensions shown on the individual bed frame before planning your bedroom layout.
How to Measure for a Single Mattress or Bed Frame
If you are replacing a mattress, measure the internal sleeping area of the existing bed frame rather than the outside edges. Check the width from side to side and the length from the head end to the foot end, then compare those measurements with the mattress specification.
Replacing a Mattress in an Existing Frame
For a standard UK single, you would normally expect the mattress space to be around 90 x 190cm. However, it is still worth checking the actual measurements, particularly with older, imported or non-standard frames. Do not rely on the word Single alone if you are unsure.
Measuring the Bedroom for a New Bed
When buying a complete bed, switch from the mattress dimensions to the external dimensions of the frame. Check the overall width and length, as well as the headboard height and the space needed to open doors, wardrobes or underbed drawers.
It is also sensible to consider delivery access, especially if the design includes a large headboard or substantial frame sections. From a styling point of view, the same mattress size can feel very different depending on the frame: slim metalwork creates a lighter outline, while timber and upholstered designs usually have more visual weight and texture.
Endurance Beds Insight: Before ordering, mark out the full external bed dimensions on the floor with masking tape. This gives a much more realistic idea of how the bed will sit in the room than marking only the 90 x 190cm mattress area.
Single vs Small Single Mattress Sizes
A standard UK single mattress measures 90 x 190cm, while a small single measures 75 x 190cm. Both are commonly the same length, but the standard single provides an extra 15cm of sleeping width.
| Mattress Size | Width | Length |
|---|---|---|
| Small Single | 75cm | 190cm |
| Single | 90cm | 190cm |
A small single can be useful where bedroom width is particularly restricted, while a standard single offers a little more room without moving into a larger bed size. The difference may seem modest on paper, but 15cm can have a noticeable effect both on sleeping space and on how comfortably the bed fits alongside wardrobes, desks or bedside furniture.
If you are deciding between the two, see our small single bed size guide for a more detailed comparison of where this narrower size can work well.
UK vs European Single Mattress Sizes
UK and European single mattresses are not always the same size, so it is important to check the measurements in centimetres rather than relying on the word Single.
A standard UK single mattress is usually 90 x 190cm. Across European ranges, 90 x 200cm is a common single size, giving an extra 10cm in length, although dimensions can vary between manufacturers and markets.
This difference matters if you are pairing a mattress with an imported frame or replacing a mattress on a European-size bed. A UK single mattress may leave extra space at the foot of a 200cm-long frame, while a longer European mattress will not fit correctly into a frame designed for a 190cm mattress.
For the best fit, always match the actual width and length shown in the product specification rather than assuming that two products labelled Single are interchangeable.
Does Single Mattress Depth Matter?
Mattress depth does not change the standard 90 x 190cm dimensions of a UK single mattress, but it can affect how the finished bed looks, feels and fits within the frame.
A deeper mattress will increase the overall height of the sleeping surface and may require deeper fitted sheets. It can also change the proportions of the bed visually, particularly on upholstered or decorative frames where a thicker mattress may cover more of the headboard or side detailing.
Depth is especially important with designs that specify a maximum mattress height, such as some bunk beds and high sleepers. In these cases, always follow the individual bed specification rather than assuming that any single mattress will be suitable.
Before ordering, check both the mattress depth and the height of the bed base so you have a clear idea of the final sleeping height and overall proportions.
What to Check Before Buying
Before ordering a single mattress or bed frame, it is worth checking a few measurements together rather than relying on the size name alone.
- Mattress dimensions: confirm whether you need the standard UK single size of 90 x 190cm.
- Internal frame size: measure the sleeping area if you are keeping an existing bed frame.
- External frame dimensions: check the full width and length when planning the bedroom layout.
- Mattress depth: consider the finished bed height and any maximum depth stated for the frame.
- Room clearance: allow enough space for doors, wardrobes, drawers and comfortable movement around the bed.
- Delivery access: check stairs, doorways and tight turns for larger frame sections or headboards.
Once the measurements work, the frame style can be chosen around the room itself. Slim metal frames tend to create a lighter outline, natural timber introduces warmth and texture, while upholstered designs can give a softer, more substantial finish. The mattress size may be the same, but the visual impact of the finished bed can be very different.
Final Thoughts
A standard UK single mattress measures 90 x 190cm, but the complete bed frame will usually take up more floor space. Checking both the mattress size and the external frame dimensions will help avoid fit issues and make it easier to plan the room accurately.
Once the measurements are right, you can focus on the frame style, finish and materials that suit the bedroom. Explore our 3ft Single Beds to compare designs made for a standard UK single mattress.
Frequently Asked Questions
What Size Fitted Sheet Do I Need for a UK Single Mattress?
For a standard UK single mattress measuring 90 x 190cm, choose a fitted sheet designed for a 3ft single mattress. Check the pocket depth as well as the width and length, particularly if you have a deeper mattress.
What If My Bed Frame Measures 90 x 200cm?
A frame measuring 90 x 200cm is longer than a standard UK single mattress, which is normally 90 x 190cm. Before buying a replacement mattress, check the frame specification or manufacturer guidance rather than assuming that any mattress labelled Single will fit correctly.
Do Two UK Single Mattresses Make a Super King?
Not exactly. Two standard UK single mattresses placed side by side would measure approximately 180 x 190cm, while a standard UK Super King mattress is typically 180 x 200cm. The widths match, but the Super King is usually 10cm longer.
Nicholas Forth
Director
Nick has put his 15 years of industry expertise into his blog posts. With the goal of making customers more informed, he provides insight into bed design, durability, and the best choices for different lifestyles and needs. His writing combines technical knowledge with practical advice, helping readers understand what really matters when choosing a bed or mattress. Whether breaking down material differences, exploring trends in bedroom design, or sharing tips on maximising comfort, he ensures every post is both educational and easy to follow.
